Apparatus for automatically charging a stack magazine of a bag-making machine with tube section stacks

ABSTRACT

A roller bed serves to receive the tube section stacks from a feeder conveyor. A movable transfer rake has tine rods which are about as long as the rollers of the roller bed and in one end position extend between the rollers of the roller bed. The rake is movable relative to the roller bed in a vertical direction to take over the stacks and subsequently in a substantially horizontal direction to its other end position. A stripper is movable to a position behind the stack of tube sections lying on the transfer rake above the stack magazine and remains in stripping position during the return movement of the transfer rake.

United States Patent Inventors Willi Stork Tecklenburg;

Karl Haupt, Wolbeck via Munster, both of Germany Feb. 24, 1970 Oct. 19,197 1 Windmoller & Holscher Lengerich of Westphalia, Germany by saidHaupt Feb. 27, 1969 Germany Appl. No. Filed Patented Assignee PriorityAPPARATUS FOR AUTOMATICALLY CHARGING A STACK MAGAZINE OF A BAG-MAKINGMACHINE WITH TUBE SECTION STACKS 13 Claims, 3 Drawing Figs.

US. Cl 93/93 HT, 53/78, 93/59 ES, 93/93 DP Int. Cl B31b 1/98, B'31b1/08, B65b 67/00 Field of Search 93/93, 59 ES; 53/78 References CitedUNITED STATES PATENTS 3,380,222 4/1968 Bergmann 93/93 HT 3,397,6248/1968 Currie 93/93 HT 3,424,113 1/1969 Dickmann... 93/93 HT 3,431,8283/1969 Crawford 53/78 X 3,442,186 5/1969 Hirose 93/93 M 3,474,59310/1969 Hartbauer 93/93 DP FOREIGN PATENTS 235,539 5/1967 U.S.S.R 93/93HT Primary Examiner-Wayne A. Morse, Jr. Attorney-Fleit, Gipple &Jacobson ABSTRACT: A roller bed serves to receive the tube sectionstacks from a feeder conveyor. A movable transfer rake has tine rodswhich are about as long as the rollers of the roller bed and in one endposition extend between the rollers of the roller bed. The rake ismovable relative to the roller bed in a vertical direction to take overthe stacks and subsequently in a substantially horizontal direction toits other end position. A

stripper is movable to a position behind the stack of tube sectionslying on the transfer rake above the stack magazine and remains instripping position during the return movement of the transfer rake.

APPARATUS FOR AUTOMATICALLY CHARGING A STACK MAGAZINE OF A BAG-MAKINGMACHINE WITII TUBE SECTION STACKS Bag-making machines for making bagsfrom tube sections are provided with stack magazines, into which stacksof tube sections must be continually placed during the operation of themachine. These stacks of tube sections have previously been placed intothe stack magazines by hand. In view of the high-output rates of modernbag-making machines, a plurality of operators are required to place newstacks of tube sections into the stack magazine of the machine. Thisoperation is difficult and must be performed with great care because thestacks of tube sections have a heavy weight in view of the largedimensions of the tube sections which are required for the manufactureof bags and great care is required during the manual handling of thestacks of tube sections and particularly as they are placed into thestack magazine if a relative shifting of the tube sections, which areloosely superimposed in the stack, is to be avoided. A shifting of thetube sections during manual handling is particularly liable to occur ifthe bags are made from smooth material, particularly plastics materialsheeting. Owing to the high flexibility and large dimensions of the tubesections, the repositioning of shifted tube sections requires a largetime. Shifted tube sections which are not repositioned will result introuble in the operation of the bagmaking machine and in bags which mustbe rejected.

It is an object of the invention to eliminate these disadvantages in thecharging of stack magazines with stacks of tube sections in thatapparatus for automatically charging the stack magazine is provided toperform the work previously carried out by the operators.

The apparatus according to the invention is characterized by a rollerbed for receiving the tube section stacks from a feeder conveyor, amovable transfer rake having tine rods, which are about as long as therollers of the roller bed and which in one end position extend betweenthe rollers of the roller bed, the rake being movable relative to theroller bed in a vertical direction to take over the stacks andsubsequently in a substantially horizontal direction to its other endposition, in which the rake is disposed above the stack magazine, and astripper which is movable to a position behind the stack of tube:sections lying on the transfer rake above the stack magazine and whichremains in stripping position during the return movement of the transferrake.

The apparatus according to the invention can be used to take over stacksof any desired number of exactly aligned tube sections, which stackshave been formed at the discharge end of a tubing extruder and may haveany desired dimensions, to feed these stacks to the stack magazine ofthe bag-making machine and to deliver the stacks to said magazine,without an unpermissible shifting of individual tube sections in thestack. The transfer capacity of the awaratus is sufficient for acharging even of high-duty bag-making machines with tube sections at therate which is required for a continuous production by such machines. Itwill be understood that the apparatus is suitable for an automaticfeeding of stacks of workpieces to other machines for processing flatworkpieces.

In a development of the invention, the transfer rake is guided by guiderails, which are designed so that the transfer rake extends parallel tothe rollers of the roller bed when the rake is disposed adjacent to saidbed, and parallel to the bottom of the stack magazine when the rake isdisposed adjacent to the stack magazine. In a preferred embodiment ofthe transfer rake, the tine rods thereof are secured by bracketsextending at right angles to the tine rods to a common carrying bar,which at its ends is secured to lateral running gears, which haverollers rolling on the guide rails, This transfer rake is simple indesign and may have a sufficiently large width in view of the oftenlarge lengths of the stacks of tube sections to be transferred.According another feature of the invention, the transfer rake isreciprocated between the roller bed and the stack magazine in a simplemanner by a slider linkage having rocker arms provided with sliders,which slide in guide sleeves, which are pivotally mounted on thecarrying bar.

According to another feature of the invention, the tine rods of thetransfer rake are provided with rollers, which are rotatable in thelongitudinal direction of the tine rods and which receive the stack oftube sections as the roller bed is lowered relative to the transferrake.,The rollers have the advantage that the stack of tube sections isstripped by the stripper from the transfer rake into the stack magazineof the bag-making machine. without friction so that a relative shiftingof the tube sections in the stack is also avoided.

The transfer of the stacks arriving on the roller bed to the transferrake is controlled according to the invention by a stop, which extendsparallel to the tine rods and which for an exact alignment of the stacksis adjustable transversely to the tine rods of the transfer rake, i.e.,in the direction of travel on the roller bed, relative to the stackmagazine to be fed, said stop being provided with a limit switch, whichis disposed in the path of the stacks of tube sections arriving on theroller bed and deenergizes the means for driving the roller bed and atthe same time energizes the reciprocating drive means for the roller bedto lower the same relative to the the transfer rake. To ensure that thestack of tube sections engages the stop as smoothly as possible, it isanother feature of the invention that the roller bed is adapted to bedriven at two different peripheral velocities, the higher of which isequal to the delivery speed of the feeding conveyor delivering thestacks to the roller bed whereas the lower of said velocities isselected so that an excessively strong impact of the tube section stackon the stop is avoided. According to another proposal of the invention,the change of the roller bed drive to the lower speed and thedeenergization are effected by means of a sensing lever, which ismounted on the described stop and disposed in the path of the stacks oftube sections arriving at the high speed of travel. Two switches areassociated with the sensing lever. One of said switches is operated tochange the speed of travel to the lower value when the stack is at asufficiently large distance from the position in which it impinges onthe stop. The other of said switches acts as a limit switch, whichdeenergizes the roller bed drive, now operating at a low speed,immediately before the stack impinges on the stop and which energizesthe reciprocating drive means in the sense which has been describedhereinbefore.

According to another proposal of the invention the transfer movement ofthe transfer rake fed with a stack of tube sections is initiated by asensor, which senses the height of the stack in the stack magazine ofthe bag-making machine and initiates said transfer movement-when thestack in the magazine has been used up in the bag-making machine but fora residue which is at least sufficient for a period of time which isequal to the period of time required to charge the stack magazine with anew stack of tube sections, This control of the transfer rake alwaysensures the correct charging of the stack magazine with a new stackbefore the supply contained in the magazine has been used up and withouta formation of an excessively high stack in the magazine.

According to another feature of the invention, the forward and returnmovements of the transfer rake are limited by two limit switches, one ofwhich terminates the forward movement of the transfer rake to the stackmagazine and at the same time energizes the reciprocating motor for thestripper to lower the same whereas the other limit switch terminates thereturn movement of the transfer rake to the roller bed and at the sametime energizes said reciprocating motor to lift the stripper to itsinitial position and also energizes the reciprocating drive means forthe roller bed to lifi the same relative to the transfer rake andenergizes the means for driving the rollers. This interlocked controlensures that the operation of the stripper and the return stroke of theroller bed so that it can receive a new stack of tube sections will beperformed in time.

In accordance with the invention. the up and down movement of thestripper is also controlled by two limit switches, one of whichterminates the descent of the stripper to its stripping position andalso energizes the drive motor for the transfer rake to return the sameto the roller bed. This arrangement ensures that the transfer rake willbe stationary, as required, during the descent of the stripper to itsstripping position, and that the stripping FIG. 3 is a top plan viewshowing the stop which is provided with a sensing lever and engageableby the stacks arriving on the roller bed.

The apparatus which is shown in the drawing comprises a rectangularframe 1. Guide rails 2, 2' are secured to opposite sides of the frameand like booms of a crane protrude beyond the base area of the frame.The guide rails consist of steel channels and are parallel to each otherand secured to the frame in such a manner that the open sides of thechannels face each other. The channels are angled, extendinghorizontally in the frame and being upwardly inclined outside the frame.As is apparent in FIG. 2, the height of the frame and the overhang ofthat portion of the guide rails 2, 2 which protrudes over the frame areselected in view of the receiving end of a bag-making machine 3 so thatthe protruding portions of the guide rails extend above a stack magazine4 of a rotary feeder 5 of the bag-making machine 3 and approximatelyparallel to the bottom of the magazine.

A horizontal roller bed 6 is mounted in the frame 1 and can be liftedand lowered therein in such a manner that in the upper end position,indicated with dash-dot lines in FIG. 1, rollers 7 of the roller bed liein one plane with feeder conveyors, such as roller beds 8, 8', whichfeed the stacks of tube sections formed at the discharge end of a tubingextruder, which is not shown on the drawing. The length and width of theroller bed 6 are, respectively, at least as large as the largest lengthand width of the tube sections or of the stacks Srfonned by said tubesections. The rollers 7 are driven by known means, such as a drive belt,to rotate in the same sense. The roller drive can be switched betweentwo roller speeds. Besides, the sense of rotation of the rollers can bereversed. The reciprocating drive means for the roller bed and the meansfor driving the rollers consist of known elements and are not shown inthe drawing. The up and down movement of the roller bed is limited bytwo limit switches 9, 10, which are diagrammatically indicated.

Running gears 11, 11' have rollers 12, 12' running in the guide rails 2,2'. A preferably round carrying bar 13 is secured at its ends to therunning gears and extends throughout the width of the apparatus andparallel to the plane of conveyance defined by the roller bed 6. Amultiplicity of tine rods 14, which are parallel to the rollers 7 of theroller bed 6, are secured to the carrying bar by means of dependingbrackets extending at right angles to the tine rods 14. The parts 13,14, 15 together form a transfer rake. The tine rods are regularly spacedalong the carrying bar 13 by the same distance tas the rollers 7 of theroller bed 6 but are staggered from the rollers 7 by one-half thatdistance so that the tine rods are aligned with the gaps between therollers of the roller bed, as is shown in FIG. 1. The width of each gapbetween the rollers exceeds the width of the tine rods so that therollers 7 can pass between the tine rods 14 during the up and downmovement of the roller bed 6. The roller bed 6 and the transfer rake 13,14, 15 are so related to each other that the rollers 7 protrude over thetine rods 14 when the roller bed 6 is in its upper end position,indicated in dash-dot lines in FIG. 1, and the rollers are below thetine rods when the roller bed is in its lower end position. The tinerods carry a multiplicity of small rollers 16, which protrude above theprofile of the tine rod and rotate in the Iongitudinal direction of thetine rods.

The transfer rake 13-16 is movable on the guide rails 2, 2' by means ofthe running gears 11, 11'. As is apparent from FIG. 2, it assumes theend position indicated in solid lines adjacent to the roller bed 6 andthe other end position, which is indicated in dash-dot lines, adjacentto the stack magazine 4. A slider linkage 17, 18, 18' is provided toreciprocate the transfer rake and comprises a crank 17, which is drivenby a gear motor 19 and extends into a slot 20 (FIG. 2) of a rocker arm18. The rocker arm 18 is secured to a shaft 21, which is parallel to thecarrying bar 13 and rotatably mounted in the machine frame. Anotherrocker arm 18', which has the same dimensions as the lever 18 andextends parallel to the rocker arm 18, is secured to the shaft 21. Thetwo rocker arms carry sliders 22, 22, which slide in guide sleeves 23,23', which are pivotally mounted on the round carrying bar 13 adjacentto the two running gears 11, 11. The two end positions of the transferrake 13, 14, 15 shown in FIG. 2 are controlled by two limit switches 24,25, which are operated by a cam wheel 26, which is mounted on shaft ofthe crank 17.

A guide rod 27 which is parallel to the carrying bar 13 is secured tothe two running gears 11, 11. A holder 28 for a stop 29 is slidable onthe guide rod 27 and can be fixed in position thereon. When the transferrake 13, 14, 15 is in the end position shown in solid lines in thedrawing, the stop 29 is disposed in the path of the tube section stacksSrarriving on the roller bed 6 and is adjustable transversely to thetine rods 14, i.e., in the direction of travel on the roller bed 6. Thisstop permits of an exact alignment of the arriving stacks of tubesections relative to the stack magazine 4. A sensing lever 30 (FIG. 3)is rotatably mounted on the stop 29 and has a sensing arm, which isdisposed in the path of the tube section stacks Starriving on the rollerbed 6. Two switches 31, 32 are associated with the sensing lever. Theswitch 31 is a changeover switch, which is operable to change the meansfor driving the rollers 7 of the roller bed 6 from the high-deliveryspeed to a much lower conveying speed. This change is efiected when thearriving stack of tube sections is spaced from the stop 29 by a safetydistance which is so large that it permits of a deceleration of thestack to the lower conveying speed. The switch 32 is a limit switch,which deenergizes the means for driving the rollers 7, now at a lowspeed, immediately before the stack of tube sections impinges on thestop. The changeover switch 31 may be omitted if the mass of the stackand the delivery speed of the stack are so small that there will be noundesirably strong impact on the stop.

Two bracket arms 33, 33 are secured to the guide rails 2, 2'. A stripper34 extending between the guide rails is mounted on the bracket arms 33,33' for an up and down pivotal movement. The stripper consists of twolateral lever arms 35, 35', each of which is rotatably mounted on one ofthe two bracket arms. The free ends of the lever arms are rigidlyconnected by a crossmember 36, to which a plurality of depending fingers37 are secured. The arrangement of the stripper is such that in itsupper end position, shown in solid lines, it is disposed outside therange of movement of the transfer rake 13, 14, 15 and in its lower endposition, shown in FIG. 2, its fingers rest on the rear transverse wallof the stack magazine 4. As is apparent from FIG. 1, the fingers 37 arealigned with the gaps between the tine rods 14 and have such a smallwidth that they can extend freely between the tine rods 14 of thetransfer rake. The stripper is moved up and down by a reciprocatingmotor 39 and a lever 38. The up and down movement of the stripper islimited by two limit switches 40, 41.

A guide rod 42 (FIG. 2) is secured to the two bracket arms 33, 33'. Aholder 43 for a reflecting photoelectric sensor 44 is horizontallyslidable on the guide rod 42 and can be fixed in position thereon. Thereflecting photoelectric sensor 44 is vertically slidable on a guide inthe holder and can be fixed in position thereon. The photoelectricsensor emits a sensing ray 45 through the stack magazine 4 on areflector 46, which is mounted on the rear wall of the magazine. Theelevation of the photoelectric sensor may be adjusted so that the samedelivers a control pulse when the stack in the stack magazine from whichthe bag-making machine 3 is fed has any desired residual height yatwhich the light ray is no longer blocked.

The means for driving the various elements are interlocked as follows inorder to ensure a proper sequence of operations in the apparatus:

a. The limit switch 25 terminates the forward movement of the transferrake 13, 14, 15 to the stack magazine and at the same time energizes thereciprocating motor 39 to lower the stripper 34. b. The limit switch 40terminates the descent of the stripper 34 to its stripping position andat the same time energizes the drive motor 19 to return the transferrake 13, l4, l5.

c. The limit switch 24 terminates the return movement of the transferrake 13, 14, 15 and at the same time energizes the reciprocating motor39 to lift the stripper 34, also energizes the reciprocating drive meansfor the roller bed 6 in the lifting sense and energizes the means fordriving the rollers 7 of the roller bed 6.

d. The limit switch 32 which is carried by the stop 29 terminates theadvance of the stack of tube sections on the roller bed 6 and at thesame time energizes the reciprocating drive means for the roller bed tolower the same.

The mode of operation of the above-mentioned embodiment of the apparatusaccording to the invention will now be explained.

The apparatus will remain in its initial position, shown on the drawing,until the stack Srdisposed in the stack magazine has been used up by thebag-making machine 3 to a residual height y so that the sensing ray 45emitted by the reflecting photoelectric sensor 44 can reach thereflector 46. The photoelectric sensor 44 then initiates the cycle ofoperations of the apparatus by energizing the drive motor 19 to advancethe transfer rake l3, l4, 15 along the guide rails 2, 2' to the endposition shown in dash-dot lines so that the tube section stack Stdisposed on the rake is carried to a position over the stack magazine 4.This advance is terminated by the limit switch 25, which deenergizes thedrive motor 19 and at the same time energizes the reciprocating motor 39to lower the stripper 34. The descending stripper engages the tubesection stack resting on the transfer rake from the rear and the fingers37 of the stripper move between the tine rods 14 and come to rest on therear wall of the stack magazine 4. The limit switch 40 limits thedescent of the stripper 34 and at the same time energizes the drivemotor 19 to return the transfer rake l3, l4, 15. During the returnmovement of the transfer rake, the fingers 37 of the stripper hold thestack in position so that the same is stripped form the returning rakeand received by the stack magazine. The freely rotatable rollers 16carried by the tine rods ensure that the stack of tube sections slideswithout friction from the tine rods 14. The limit switch 24 limits thereturn movement of the transfer rake 13, l4, 15 in the initial positionshown in solid lines and at the same time energizes the reciprocatingmotor 39 to lift the stripper 34, also energizes the reciprocating drivemeans for the roller bed 6 to lift the same, and energizes the means fordriving the rollers 7 of the roller bed. This interlocked control causesthe stripper 34 to be lifted to its initial position, which is shown inFIGS. 1 and 2 and in which it is stopped by the limit switch 41. At thesame time, the roller bed 6 is moved from its lower end position, shownin solid lines, to its upper end position, shown in dashdot lines, andthe rollers 7 begin to rotate. In its upper end position, controlled bythe limit switch 9, the roller bed is disposed on the same plane as thefeeder conveyors 8, 8' and its rollers protrude above the supportingplane defined by the tine rods 14 of the transfer rake. The limit switch9 opens a locking means, known per se, which is provided in the feederconveyor 8, 8' so that the same delivers the next stack of tube sectionsto the roller bed, which advances said stack so that the same strikesthe sensing lever 30 above the tine rods 14. The limit switch 31associated with the sensing lever 30 now effects a change from thehigh-delivery speed to the lower conveying speed, at which the stack oftube sections is advanced as far as to the stop 29. Shortly before thestack reaches the stop 29, the sensing lever 30 operates the limitswitch 32 to stop the rollers 7, render the locking means in the feederconveyor 8 effective and energize the reciprocating drive means for theroller bed to lower the same. As the roller bed 6 descends, the stackcomes to rest on the tine rods 14 of the transfer rake l3, l4, 15. Thelimit switch terminates the descent of the roller bed and the entirecycle of operation of the apparatus, which is new again in its initialposition.

The elevation of the sensing ray 45 is suitably selected so that theresidual height y of the stack in the stack magazine is so large thatthe time in which the residual stack y is used up by the bag-makingmachine is equal to the time required by the transfer rake l3, 14, 15 tomove the stack thereon to the stack magazine and to strip the stack intothe magazine. With that optimum setting of the photoelectric sensor44serving to initiate the cycle of operations of the apparatus, thestacks of tube sections may have the optimum height, which correspondsto the height to which the stackmagazine can be tilled. l i

If it is more desirable to deliver the stacks to the roller bed by thefeeder conveyor 8 on the opposite side, e.g., for

reasons of layout, it will be sufficient to reverse the sense ofrotation of the rollers 7 of the roller bed and to secure the stop plate29 to its holder in a position in which the stop plate 29 is turnedthrough and laterally offset by a suitable distance. The apparatus willthen properly perform the above-described cycle of operation when thetube section stacks are delivered from the right.

The apparatus may be nondetachably connected to the bagmaking machine toform a permanent part of the latter. The embodiment shown in the drawingis easily movable on floor rollers 47 and provided with locking means 48by which it can be firmly but detachably connected to the machine frameof the bag-making machine. This apparatus may be used in conjunctionwith each of a plurality of bag-making machines, as required.

We claim:

1. Apparatus for automatically charging a stack magazine of a bag-makingmachine with tube section stacks, characterized by a roller bag (6) forreceiving the tube section stacks (St) from a feeder conveyor (8, 8'), amovable transfer rake (13, 14, 15) having tine rods (14), which areabout as long as the rollers (7) of the roller bed and which in one endposition extend between the rollers (7) of the roller bed (6), the rakebeing movable relative to the roller bed in a vertical direction to takeover the stacks and subsequently in a substantially horizontal directionto its other end position, in which the rake is disposed above the stackmagazine (4), and a stripper (34), which is movable to a position behindthe stack of tube sections lying on the transfer rake (13, 14, 15) abovethe stack magazine and which remains in stripping position during thereturn movement of the transfer rake.

2. Apparatus as set forth in claim 1, characterized in that the transferrake (l3, l4, 15) is guided by guide rails (2, 2'), which are designedso that the transfer rake extends parallel to the rollers (7 of theroller bed (6) when the rake is disposed adjacent to said bed, andparallel to the bottom of the stack magazine (4) when the rake isdisposed adjacent to the stack magazine.

3. Apparatus as set forth in claim 2, characterized in that the tinerods (14) of the transfer rake are secured to a common carrying bar (13)by brackets (15) extending at right angles to the tine rods and thecarrying bar is secured at its ends to lateral running gears (11, l lwhich with their rollers (l2, 12) roll on the guide rails (2, 2').

4. Apparatus as set forth in claim 2, characterized in that the transferrake (l3, l4, 15) is reciprocable by a slider linkage (17, l8, 18'),which has rocker arms (18, 18') carrying sliders (22, 22'), which slidein guide sleeves (23, 23'), which are pivoted on the carrying bar (13).

5. Apparatus as set forth in claim 1, characterized in that the tinerods (14) of the transfer rake (13, 14, 15) carry rollers (16), whichare rotatable in the longitudinal direction of the tine rods and whichreceive the tube section stack (S1).

6. Apparatus as set forth in claim 1, characterized by a stop (29),which extends parallel to the tine rods (14) and is adjustable in thedirection of travel on the roller bed (6) and carries a limit switch(32), which is disposed in the path of the tube section stacks arrivingon the roller bed and which deenergizes the means for driving the rollerbed and at the same time energizes the reciprocating drive means tolower the roller bed relative to the transfer rake.

7. Apparatus as set forth in claim 1, characterized in that the rollerbed (6) is adapted to be driven at two different peripheral velocitiesand the higher of said velocities is equal to the delivery speed of thefeeder conveyor (8, 8') delivering the tube section stacks (St) to theroller bed whereas the lower of said velocities is selected so that anexcessively strong impact of the tube section stack on the stop (29) isavoided.

8. Apparatus as set forth in claim 6, characterized by a sensing lever(30), which is mounted on the stop (29) and disposed in the path ofmovement of the tube section stacks (S!) as they are delivered at thehigher speed, and two switches (31, 32), which are associated with saidsensing lever (30) and one of which (31) is operated to change the speedof travel on the roller bed to the lower value when the stack is at asufficiently large distance (x) from the position in which it impingeson the stop (29), whereas the other switch is a limit switch andimmediately before the tube section stack impinges on the stopdeenergizes the means for driving the rollers (7) and at the same timeenergizes the reciprocating drive means for the roller bed to lower thesame.

9. Apparatus as set forth in claim 1, characterized by a sensor (44, 45,46), which senses the height (y) of the stack in the stack magazine (4)of the bag-making machine (3) and serves to initiate the transfermovement of the transfer rake l3, 14, fed with a tube section stack(St), as soon as the stack in the magazine has been used up but for aresidue.

10. Apparatus as set forth in claim 1, characterized in that the forwardand return movements of the transfer rake (l3, l4, 15) are limited bytwo limit switches (24, 25), one of which (25) terminates the forwardmovement of the transfer rake to the stack magazine (4) and at the sametime energizes the reciprocating motor (39) for the stripper (34) tolower the same, whereas the limit switch (24) terminates the returnmovement of the transfer rake to the roller bed (6) and at the same timeenergizes said reciprocating motor to lift the stripper to its initialposition and also energizes the reciprocating drive means for the rollerbed to lift the same relative to the transfer rake and energizes themeans for driving the rollers.

11. Apparatus as set forth in claim 1, characterized in that the up anddown movement of the stripper (34) is limited by two limit switches (40,41), one of which (40) terminates the descent of the stripper to itsstripping position and at the same time energizes the drive motor (19)for the transfer rake (l3, l4, 15) to return the same to the roller bed(6).

12. Apparatus as set forth in claim 1, characterized in that the senseof rotation of the rollers (7 of the roller bed (6) is reversible.

13. Apparatus as set forth in claim 1, characterized in that it ismovable on rollers (47).

1. Apparatus for automatically charging a stack magazine of a bag-makingmachine with tube section stacks, characterized by a roller bag (6) forreceiving the tube section stacks (St) from a feeder conveyor (8, 8''),a movable transfer rake (13, 14, 15) having tine rods (14), which areabout as long as the rollers (7) of the roller bed and which in one endposition extend between the rollers (7) of the roller bed (6), the rakebeing movable relative to the roller bed in a vertical direction to takeover the stacks and subsequently in a substantially horizontal directionto its other end position, in which the rake is disposed above the stackmagazine (4), and a stripper (34), which is movable to a position behindthe stack of tube sections lying on the transfer rake (13, 14, 15) abovethe stack magazine and which remains in stripping position during thereturn movement of the transfer rake.
 2. Apparatus as set forth in claim1, characterized in that the transfer rake (13, 14, 15) is guided byguide rails (2, 2''), which are designed so that the transfer rakeextends parallel to the rollers (7) of the roller bed (6) when the rakeis disposed adjacent to said bed, and parallel to the bottom of thestack magazine (4) when the rake is disposed adjacent to the stackmagazine.
 3. Apparatus as set forth in claim 2, characterized in thatthe tine rods (14) of the transfer rake are secured to a common carryingbar (13) by brackets (15) extending at right angles to the tine rods andthe carrying bar is secured at its ends to lateral running gears (11,11''), which with their rollers (12, 12'') roll on the guide rails (2,2'').
 4. Apparatus as set forth in claim 2, characterized in that thetransfer rake (13, 14, 15) is reciprocable by a slider linkage (17, 18,18''), which has rocker arms (18, 18'') carrying sliders (22, 22''),which slide in guide sleeves (23, 23''), which are pivoted on thecarrying bar (13).
 5. Apparatus as set forth in claim 1, characterizedin that the tine rods (14) of the transfer rake (13, 14, 15) carryrollers (16), which are rotatable in the longitudinal direction of thetine rods and which receive the tube section stack (St).
 6. Apparatus asset forth in claim 1, characterized by a stop (29), which extendsparallel to the tine rods (14) and is adjustable in the direction oftravel on the roller bed (6) and carries a limit switch (32), which isdisposed in the path of the tube section stacks arriving on the rollerbed and which deenergizes the means for driving the roller bed and atthe same time energizes the reciprocating drive means to lower theroller bed relative to the transfer rake.
 7. Apparatus as set forth inclaim 1, characterized in that the roller bed (6) is adapted to bedriven at two different peripheral velocities and the higher of saidvelocities is equal to the delivery speed of the feeder conveyor (8,8'') delivering the tube section stacks (St) to the roller bed whereasthe lower of said velocities is selected so that an excessively strongimpact of the tUbe section stack on the stop (29) is avoided. 8.Apparatus as set forth in claim 6, characterized by a sensing lever(30), which is mounted on the stop (29) and disposed in the path ofmovement of the tube section stacks (St) as they are delivered at thehigher speed, and two switches (31, 32), which are associated with saidsensing lever (30) and one of which (31) is operated to change the speedof travel on the roller bed to the lower value when the stack is at asufficiently large distance (x) from the position in which it impingeson the stop (29), whereas the other switch is a limit switch andimmediately before the tube section stack impinges on the stopdeenergizes the means for driving the rollers (7) and at the same timeenergizes the reciprocating drive means for the roller bed to lower thesame.
 9. Apparatus as set forth in claim 1, characterized by a sensor(44, 45, 46), which senses the height (y) of the stack in the stackmagazine (4) of the bag-making machine (3) and serves to initiate thetransfer movement of the transfer rake (13, 14, 15) fed with a tubesection stack (St), as soon as the stack in the magazine has been usedup but for a residue.
 10. Apparatus as set forth in claim 1,characterized in that the forward and return movements of the transferrake (13, 14, 15) are limited by two limit switches (24, 25), one ofwhich (25) terminates the forward movement of the transfer rake to thestack magazine (4) and at the same time energizes the reciprocatingmotor (39) for the stripper (34) to lower the same, whereas the limitswitch (24) terminates the return movement of the transfer rake to theroller bed (6) and at the same time energizes said reciprocating motorto lift the stripper to its initial position and also energizes thereciprocating drive means for the roller bed to lift the same relativeto the transfer rake and energizes the means for driving the rollers.11. Apparatus as set forth in claim 1, characterized in that the up anddown movement of the stripper (34) is limited by two limit switches (40,41), one of which (40) terminates the descent of the stripper to itsstripping position and at the same time energizes the drive motor (19)for the transfer rake (13, 14, 15) to return the same to the roller bed(6).
 12. Apparatus as set forth in claim 1, characterized in that thesense of rotation of the rollers (7) of the roller bed (6) isreversible.
 13. Apparatus as set forth in claim 1, characterized in thatit is movable on rollers (47).